The present invention relates generally to clinical instruments for the examination of eyes, and more particularly to a portable instrument for self-examination of the pupil of the eye.
Pupilometer instruments known in the art prior to the invention generally comprise large, substantially stationary devices which have significant power requirements and which need a separate operator to focus and align optics of the devices, to make measurements and to interpret results.
The invention described herein comprises a compact, portable subject operated instrument for rapid and accurate measurements of the eye in substantially any environment, and has particular field utility as a pupilometer in the self-administered examination of pupil dilation. The invention includes a flashlamp and power source for illuminating the eye a lens system for projecting an image of the eye onto photographic film, and a calibrated grid imaged onto the film simultaneously with the image of the eye. A padded forehead light shield excludes extraneous light during a measurement. The invention combines a light emitting diode system for accurate alignment of the eye with a telecentric lens system and calibrated photographic image in a small portable pupilometer having certain advantages over pupilometer instruments previously known in the art. For example, the invention provides eye image magnification which does not change with position relative to the instrument and has a very large depth of focus which compensates for variation in distance to various subjects' eyes corresponding to various facial contours, which ensures consistent resolution in the instrument from subject to subject and eliminates any need for a separate operator for the instrument.
It is therefore a principal object of the invention to provide an improved eye examination instrument.
It is another object of the invention to provide an instrument for self-administered examination of the pupil of an eye.
It is a further object of the invention to provide a subject operated pupilometer for self-examination of pupil dilation.
It is yet a further object of the invention to provide a portable subject operated pupilometer.
These and other objects of the invention will become apparent as the detailed description of representative embodiments proceeds.